Pulverizing apparatus



Aug 13 1929 F H. DANIELS 1,724,072

PULVERI Z ING AIPARATUS Filed Aug. 21, 1926 UMH,

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FRED JEL. DlltNIlEdLS-, 0F .WORCESTJER, MASSACHUSETTS, ASSIGNOR vTO RILEY STKER GRlPR''lLllUN, 0F WUBGJESTER, MASSACHUSETTS, A CURPORATION OF MASSACHUg- SETTE.

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Application led August 21, 1926. Serial No. 130,749.

Illhis invention relates to pulverizing apparatus, and more particularly to'an apparatus of the beater type. I l

` Such a machine is disclosed in the reissue patenti to Blyth, No.,16,229, in'wh-icli ma! terial is comminuted by the action @f interyiitting alternately revoluble and stationary impact bodies or pegs. 'An arrangement of this type is.` very eflicient in producing fine pulverization, but has certain inherent defects, llt is found that the power consumption is excessive when operating upon coarse materials, and thepegs are lsubject to rapid wear. Moreover, the pegs are relatively fragile, and are easily broken by hard for-` eign bodies, suchas .tramp iron, which are v frequently present in certain materials.

llt is accordingly one object of my invention to provide. a pulverizing apparatus 1n which coarse material may be efficiently reduced to a desired degree of fineness. ,"A further-object of my invention is to provide a pulverizing apparatus which is sol arranged that hardy foreign bodies entering f the `machine maybe safely eliminated with outdamage tothe pulverizing elements.

'il/Vith these and other objects 1n view, as

will be apparent to one Iskilled in the art, my f invention resides in theA combination of parts set forth lin the specification the claims appendedhereto.

.ccording to-my invention,- ll 'providela pulverizing apparatus in which `a crushing Vroll is arrangedmfor pulverlzing the material preliminarily and then feeding ity for ne pulverization to 'a second zone. lin my `pre- `ferred embodiment l make 'use' of a payir of y crushing rollsso constructedas to crushthe material between them.v ltis desirableto -prevent'damage to the rolls caused by' hard i foreign bodies, and one wayin which this may be accomplished is by mounting one roll yieldinglyby a suitable means, such as l a spring. rlhe material thus crushed preliminarily is fed at a regulatable rate to the periphery of Va second zone containing revoluble beaters, and it is there' forced Vby a fan to pass towards a centrally located outlet against the centrifugal forces set up by the revolving beaters. ln the preferred conf struction, the material is finely pulverized by alternately revoluble .and stationary impact members as it passes towards the vcentral outlet. ln order` to protect these rapdoor.

and coveredby iron whichA might enter the vcasing with the coarse material and cause serious damage, provisions are made for eliminatingsuch large hard foreign-bodies. To this end, ll space rthe crushing rolls from the peripheral path of the revolving impact members and provide room for such bodies to settle out of the entering stream and fall into a receptacle at the bottom of the casing, from which they may be removed through a trap A fan may be so located as to draw the material thru the machine on acurrent of 'air of desired volume. Revoluble re ject-or blades maybe arranged to sweep across the exit opening and hurl back into the machine any coarse particles which attempt to pass, thus serving to keep the lproduct uniformly fine.

Referring to the drawings in which like reference numerals indicate like parts:

F ig. -1 is a vertical section through the machine, I illustrated somewhat diagram- 1natically, the section being taken on the line 1 -11 of Fig. 2;

Fig. 2 is a,sectiony on the. line 2-2 fof tthrough both chambers, and is rotatably mounted v.in suitable bearingsf illustrated diagrammatically las bossesl and 17 on the casing. This' shaft maybe rotated by any suitable source of power.

l have found a toothed crushing roll to be very efficient in crushing material preliminarily. llhile one such roll can be utilized to crush material against a'fixed abutment,

l prefer to make use of a pair of rolls 20 and 21v arranged beneath a hopper 22. These rollsare keyed to rotatable shafts 24 and 25,

respectively. .These shafts may be rota-tedy by any suitable device,` and it is desirable that means be provided for varying their speed, as the load on the machine may vary. This serves to vary the rate of feedlng the coarse material to the second zone. Accord- Gti.

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ing to the simple form of construction illustrated, shaft is drivenfrom shaft 14 by a belt 27 passing over cone pulleys 29 and 30. Shaft 24 is provided with spur gears 32 which mesh with similar gears 33 on shaft 25. The power mechanism illustrated causes the impact members 41 and the crushing rolls to revolve at a definite speed ratio, and this ratio may be varied by shifting the belt 27 on the pulleys so that it is possible tovary the rate of feeding the material to therevolving( impact members without changing'r their speed. In order to permit roll 2O to yield when necessary to prevent damage from foreign bodies, shaft 24 may be mounted at each end in a bearing 35 arranged to slide horizontally away from shaft 25. Such movement is normally prevented by any suitable means such as spring 3G, as shown in. Fig. 4, located between each bearing 35 and a Xed part of the casing. A suitable pocket 38 may be provided in the casing to catch any hard foreign bodies which pass the rolls. .A slide 89 permits such bodies to be removed when desired.

.In order to further pulverize material delivered by the rolls, I utilize revoluble impact members. These members may take the.

form of pegs 41 mounted in concentric circleson a disk 42 which is keyed to the shaft 14. These pegs may cooperate with stationary pegs 44 mounted on the"` casing wall.

Although any suitable method of mounting the pegs may be used, the preferred construcvtion is fully. disclosed in the patent to Riley No. 1,576,472. If desired, a set of rejector blades 46 may be mounted on a hub/47 which is keyed to theshaft 14. These blades may be arranged to sweep across the outlet opening 11, and throw back into the pulverizing chamber any coarse particles which reach ftliem. In order to assist in'this action, a

beveled ring 48 may surround the blades.

Material is preferably carried through the machine on^-a current of air, which may be produced by a suitable fan 50, mounted on theA shaft 14 in chamber 12. Air may enter the machine through an opening llocat'ed at' any desiredy point inthe casing. Air and pulverized material may leave the fan chamber through a tangential outlet 52.

The operation of my invention will now be apparent from3 the above disclosure. Coarse material is delivered to the hopper 22 by any suitable feeding device. Shafts 24 and25 are driven'from shaft 14 which in tiirn is rotated by any suitable source of power.l Material is crushed by the rolls 20 and 21, and any hard foreign bodies will separate the rolls, pass through, and drop into pocket 38. Crushed material is drawn by the air currentv produced by fan 50, and passes against centrifugal force among the pegs41 and 44, where it is finely pulverized by impact. Fine material passes into the fan chamber and out through opening 52. Coarse particles reaching the rejectors 4G are returned to the machine for further treatment.

It will be apparent to one skilled in the art that this invention provides an cfiicient pulverizing apparatus which will reduce coarse material to a desired degree of tineness without excessive power requirements and without causing undue wear to the machine. Tlie preliminary crushing is accomplislied by rolls especially constructed to eliminate damage from hard bodies. The impact pegs are protected from contact with such hard bodies, and are utilized only for line grinding, for which purpose they are eminently adapted.

Having thus described my invention, what l claim as new, and desire to secure by Letters Patent, is:

1. A pulveiizing apparatus comprising a casing having an inlet and an outlet, a pair of rotatable crushing rolls arranged to crush coarse material, means t-o rotate said rolls, means to permit one of said rolls to yield and allow hard foreign bodies to pass without damage, a pocket suitably located to receive such hard bodies, and revoluble impact members arranged to receive material from said rolls and pulverizc said material finely.

2. A pulverizing apparatus comprising a casing provided withv an inlet for material Cfr and a centrally disposed outlet, revoluble said rolls to yield and allow the passage of hard foreign bodies without damage, a receptacle suitably disposed to receive such foreign bodies and prevent their coming into vcontact with the impact members, and means to transport material against the centrifugal action of said impact members towards said centrally disposed outlet.

3. A pulverizing apparatus comprising a casing having an inlet conduit and a centrally located outlet, a series of beaters therein revolving about the outlet which are so arranged vthat the pulverized material must pass inwardly to the outlet against the successive impacts and the outwardly impelliiig action of the beaters, and means including a crushing roll in the inlet conduit to feed 'crushed material directly to the periphery of the path of said beaters.

4. A pulvei'izing apparatus comprising a casing'having an Iinlet and an outlet, revoluble impact members therein to pulverize material fed thereto, and meansincluding a yieldingly mounted crushing roll spaced from the path of said members and arranged tor feed crushed material thereto but prevent -casing having an inlet, and an outlet,a set 3 lof revolublevimpact members arranged to pulverize the material Yfinely, means including a rotatable crushing roll to crush coarse material preliminaril'y and feed it to the impact members, power mechanism to revolve said impact members and to rotate the crushing roll at a definite speed ratio and means to vary the speed ratio.

.6. A pulverizing apparatuscomprising a casing having anlinlet and an outlet, rev- -oluble impact members therein to pulverize material fed thereto, a rotatable crushing roll spaced from the path of said members and arranged to feed crushed material directly thereto, yieldable means permitting large foreign bodies to pass said roll with the material, and a receptacle arrangedvto.- catch such Jforeign bodies and prevent their contacting with said -impact members.

7. 'A pulverizing apparatus comprising a casing having a centrally located outlet, 'a'

rftor therein having .its axis passing through the outlet, rapidly revolubl'e impact pegs on the rotor cooperating with stationary pegs on the casing to pulverize the material passing inwardly towards the outlet, means providing an inlet for material to the peripheral path ot' therotor pegs, means including a rotatable crushing roll to crush coarse m`aterial preliminarily for pulverization bysaid pegs, and means to pass acurrent of air through the apparatus from the inlet towards the outlet and remove the finely pulverized material therefrom. f Signed at Worcester, Mass., this 20th day of August, 1926. FRED-H. DANIELS. 

